The present coffee machines are mainly classified into two types: one type is the automatic stewing coffee machine which combines the grinding and stewing into one unit; the other is the separate type coffee machine with separated grinder and brewer. For example, Chinese patent No. 02209573.X disclosed an “automatic stewing device of coffee machine” which consists of a bean grinder, a filter, a driving mechanism and a water supply mechanism. However, the above automatic stewing coffee machine has the following disadvantages:
1. After stewing coffee, the coffee grounds remains in the filter cylinder of the filter. For stewing the coffee automatically and continuously, a mechanism for automatically removing the coffee grounds should be provided. Thus the automatically stewing coffee machine has a very complex structure and the manufacture cost is very high.
2. Since the stewing vessel is nonremovable, the cleaning of the stewing vessel is very inconvenient. When the users change the coffee of different flavors, flavor tainting occurs. And, inconvenience of the cleaning can also causes the health problem.
3. When the coffee machine is used to stewing coffee, a large amount of water vapor enters the coffee powder outlet channel and the grinder to moisten the coffee powder be, thereby affecting the use of coffee machine.
4. The coffee powder amount controlling mechanism in the coffee machine has a complex structure, and the manufacture cost is high.
5. The stewing water amount controlling mechanism in the coffee machine is complex, and the manufacture cost is high.
6. Since the grinder in the coffee machine is nonremovable, it is difficult to clear the remained coffee powder in the grinder. When different kinds of coffee beans are processed in the coffee machine, it is easy to cause flavor tainting of the coffee powders, so that the above coffee machine with the nonremovable grinder can not be used in a situation that users are frequently changed or by a coffee enthusiast.
7. The present grinder only uses one grinding motor. When the grinding motor stops, the coffee powder in the powder outlet channel can not be discharged, so that the coffee powder in the above grinder can not be discharged completely.
Furthermore, in use of the present coffee machine with separated grinder and brewer, the coffee beans are ground into coffee powder in the grinder, and then the coffee powder is put into the brewer to be stewed. So for this coffee machine, the ground coffee powder needs to be put into the brewer manually, it is inconvenient in use.